Chord Inversions

There’s nothing really complicated about chord inversions.  It’s one of those subjects that often gets overlooked or ignored because the perception is it’s too complicated but really, they are quite straightforward.
Take an Amaj7 chord.  This has the notes of A C# E G# which is 1, 3, 5, 7
For an inversion, all we do is start the chord on a different note than the root but keep the rest of the subsequent notes in sequence.  So this gives us:
1st inversion : C# E G# A    3, 5, 7, 1
2nd inversion : E G# A C#   5, 7, 1, 3
3rd inversion G# A C# E      7, 1, 3, 5
They really are that simple.  Now you’re probably thinking that there must be a downside, well the only ones I can think of are that your fingers might not stretch far enough for some configurations and depending where you start, you might run out of frets.  That’s it, and certainly minor issues as far as I’m concerned.  Example fingering patterns for a Maj7 chord and its 3 inversions are shown below.  ‘n’ represents the starting fret number i.e. 1 for F, 3 for G, 5 for A etc.

M7shape
Maj 7

 M7inv1Shape
1st inversion

M7inv2Shape
2nd inversion

M7inv3Shape
3rd inversion

Because you’re starting on a different note, they tend to have a different tonal quality and can be considered as different chords.  They are excellent for layering sounds and harmonies, I use this technique quite a lot in electronic music.
You can also use inversions as substitutes for the original chord.  This may sound a bit complicated but hopefully the following example makes this process easier to understand.
If we take the key of C : C D E F G A B C
C9 chord is 1, 3, 5, b7, 9 which is C E G Bb D.
Working through the inversions we have:
1st inversion  E G Bb D C
2nd inversion G Bb D C E
3rd inversion Bb D C E G
4th inversion D C E G Bb
If you know some music theory, you may see that these look like they could be chords from other Keys.  This is explored in more detail in the table below.
C9InvTable
You can probably see that I have omitted the C note because it doesn’t really fit into these inversions so for this example we will omit the C root note.  You could argue that in this case by omitting the root we have the first inversion as our first chord, the subtle difference is that we are using a C9 chord shape and omitting the root, the Em7b5 chord typically has a different shape and position.  We also won’t use the 3rd inversion as as Bb6 (b5) chord is not the easiest to use.
We can use the following shapes:
c9 (no root)
Note this is not a full shape – it does not contain the Bb note

Em7b5
Gm(6)
DAug5
Using these as chord substitutes, you could for instance use a Gm(6) instead of a C9 and this would allow you to use a minor scale from a different Key over the top of that chord.  Just be aware of any notes that may sound ‘wrong’, as I demonstrated with the C note above which was omitted from the examples.
You can use the same principles and shapes given above to work out the inversions for F9 and G9 chords. for example. This would allow you to take a basic I IV V progression and then use layering and chord substitution to open up lots of interesting harmonic possibilities.